Device for continuously folding and stacking flexible sheet materials



y 1961 F. E. HILLIKER 2,991,071

DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS Filed July 24, 1958 10 Sheets-Sheet 1 N INVENTOR.

FRANK E.- H \L\-\ KER BY yWW /QW y 1961 F. E. HILLIKER 2,991,071

- DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS '10 Sheets-Sheet 2 Filed July 24, 1958 INVENTOR.

F'IZANK, E. H\L.L\ KER,

y 1961 F. E. HILLIKER 2,991,071

DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS 10 Sheets-Sheet s Filed July 24, 1958 w E we vmm INVENTOR FRANK E. Hll-LIKER- -BY%:'% j

DNv

July 4, 1961 F. E. HILLIKER 2,991,071

DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS Filed July 24, 1958 10 Sheets-Sheet 4 INVENTOR- NK. E. H\\.\.\ KER.

F., E. HILLIKER July 4, 1961 2,991,071 DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS l0 Sheets-Sheet 5 Filed July 24, 1958 July 4, 1961 F. E. HILLIKER DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS l0 Sheets-Sheet 6 Filed July 24, 1958 INVENTOR.

FRANK E. \-\\L.LH .E,E

y 1961 F. E. HILLIKER 2,991,071

DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS Filed July 24, 1958 10 Sheets-Sheet '7 15c, \SQ \sa :4 \54- 151 l f g m II B 2 II I64- I08 A 53 51 6 i i I1 I I00 IN VEN TOR.

July 4, 1961 F. E. HILLIKER 2,991,071

DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS Filed July 24, 1958 1o Sheets-Sheet a INVENTOR.

FRANK E HH-LIKEIZ v F. E. HILLIKER 2,991,071 DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS July 4, 1961 10 Sheets-Sheet 9 FiJ .ed July 24. 1958 INVENTOR.

HlLLHER ATTO ENEYS United States Patent 2,991,071 DEVICE FOR CONTINUOUSLY FOLDING AND STACKING FLEXIBLE SHEET MATERIALS Frank E. Hilliker, Denver, Colo., assignor to Hilliker, Inc., Denver, 0010., a corporation of Colorado Filed July 24, 1953, Ser. No. 750,767 9 Claims. (Cl. 270-68) This invention relates to a mechanism for folding flexible articles formed of fabric or other similar flexible materials and, more specifically, the present invention pertains to a mechanism, or device, for folding such articles and the stacking thereof in superimposed relation relative to each other.

To place this invention in its proper perspective, it should be noted at this point that the instant invention is directed, specifically, to the resolution of a problem which apparently confronts practically every hotel, restaurant or other businesses which serve the public, and wherein the nature of the services offered to the public involves the provision of sheet materials such as, for example, towels, sheeting, linens of all kinds such as, for example, napkins, table cloths and pillow cases, to name but a few of the items normally required in such establishments as to satisfy the needs of its clientele. As is to be expected, and electing a hotel as illustrative of the problem involved, there is a substantially constant demand for toweling, bed linens, as well as table cloths and other napery. To accommodate the clientele, it is usually necessary for the establishment to set aside large working areas wherein employees engage in the tiresome, tedious and prolonged chores of hand folding most of the above referred to items. Consequently, an establishment catering to a number of transients or permanent guests must employ numerous employees (usually unskilled) to carry out the essential folding operations on the involved articles. A fortiori, the larger the type of operation of the business, the greater number of employees must be hired to accommodate the demands of the guests, with attendant increases in operating costs.

As every employer well knows, employees have, as a matter of nature, their own attitudes with respect towards their work, and while some are conscientious and meticulous, others are not. In the latter case, the costs for handling each unit rises sharply, and the resulting folded article usually has an irregular configuration which prevents the folded article from being stacked, one upon the other, which, in turn, requires larger storing areas.

Thus, and without intending any limitation upon the scope of the broad aspects of this invention, it is one of the primary objects thereof to provide a mechanical device of the type generally referred to supra wherein the working area required for its operation is materially decreased, requires but a single operator who may be unskilled, and which rapidly folds and stacks the articles at a relatively high operational speed.

A further object of this invention is to provide in the machine means for mechanically counting each article as it is stacked, together with time control means for the stacking mechanism effective to provide visual means denoting the stacking of the articles in certain preselected multiples thereof.

Another object of this invention is to provide a power operated machine or apparatus as broadly referred to above, the apparatus being operable to fold flexible sheet material elements such as towels, napkins and the like, the apparatus being operable to accomplish this function with efficiency and economy.

A still further object of this invention is to provide power driven mechanical sheet element folding apparatus which is operable to receive and fold the flexible sheets having any desired size range. v

This invention contemplates, as a further object thereof the provision of apparatus of the type described supra, wherein the folding of the flexible sheets is continuous and progressive in operation.

Another object of this invention is to provide apparatus for mechanically folding flexible sheet articles wherein the folding operation or operations are controlled, automatically, in response to the travel of the articles to be folded through the apparatus.

It has been found that there are no folding machines presently on the market which are qualified to make a square fold. Flexible and sheet materials when folded and stacked in accordance with known devices have low centers of gravity whereby the stacking of the articles to any height is substantially precluded. It is, therefore, a further object of this invention to provide a folding machine for flexible sheet materials capable of folding the material in a square fold whereby the resultant folded article may be vertically stacked in relatively high piles without encountering the possibility of tipping over, and further, such folded articles lend themselves more readily to the tying thereof in bales.

A still further object of this invention is to provide apparatus for the mechanical folding of flexible sheet material articles, the folding apparatus being non-complex in construction and assembly, inexpensive to manufacture and maintain, durable in use, and which is adaptable for operative connection with a sheet stacking unit.

It is a still further object of this invention to provide an improved sheet stacking device for stacking flexible sheet units in response to successive deliveries thereof thereto.

This invention contemplates, as a still further object thereof, the provision of a flexible sheet stacking device of the type generally described supra, the device being non-complex in construction and assembly, inexpensive to manufacture, durable in use, and which is adapted for automatic actuation, and which is positive and efficient in carrying out its assigned functions.

Other and further objects and advantages of the instant invention will become more manifest from a consideration of the following specification when read in conjunction with the annexed drawings, in which:

FIGURE 1 is a top plan view of a device or machine for continuously folding and stacking flexible sheet material, the machine being constructed in accordance with the instant invention;

FIGURE 2 is a side elevational view, partly in crosssection of the machine illustrated in FlIGURE 1, FIG- URE 2 being taken substantially on the horizontal plane of line 2--2 of FIGURE 1, looking in the direction of the arrows;

FIGURE 3 is an enlarged detail cross-sectional view taken substantially upon the vertical plane of line 33 of FIGURE 2, looking in the direction of the arrows;

3 on the vertical plane of line 6-6 of FIGURE 3, looking in the direction of the arrows;

FIGURE 7 is an enlarged fragmentary detail crosssectional view taken substantially upon the horizontal plane of line 7-7 of FIGURE 6, looking in the direction of the arrows;

FIGURE 8 is an enlarged detail fragmentary crosssectional view, FIGURE 8 being taken substantially on the vertical plane of line 88 of FIGURE 3, looking in the direction of the arrows;

FIGURE 9 is a fragmentary side elevational view of the construction shown in FIGURE 8, FIGURE 9 being taken substantially on the vertical plane of line 99 of FIGURE 8, looking in the direction of the arrows;

FIGURE 10 is a fragmentary detail cross-sectional view, partly in elevation, FIGURE 10 being taken substantially on the vertical plane of line 1010 of FIG- URE 2, looking in the direction of the arrows;

FIGURE 11 is a detail cross-sectional view, partly in end elevation, FIGURE 11 being taken substantially on the line 11-11 of FIGURE 5, looking in the direction of the arrows;

FIGURE 12 is a detail cross-sectional view of certain component elements of this invention illustrated in FIG- URE 11, FIGURE 12 being taken on the horizontal plane of line 12-12 of FIGURE 11, looking in the direction of the arrows;

FIGURE 13 is a fragmentary detail cross-sectional view taken substantially on the vertical plane of line 1313 of FIGURE 11, looking in the direction of the arrows, and illustrating a sheet of flexible material as being fed towards and into a sheet pickup device for subsequently elfecting a first fold therein;

FIGURE 14 is a detail cross-sectional view similar to FIGURE 13, FIGURE 14 illustrating the pickup means having been rotated to carry the leading edge of the flexible sheet upwardly on a cylindrical roller and just prior to the operation of automatic means for effecting release of the leading end so that as the same leaves the cylinder, the leading end of the flexible sheet becomes substantially co-extensive with the trailing end thereof;

FIGURE 15 is a fragmentary detail cross-sectional view illustrating a micro switch and cam member for alternately automatically operating a brake device or means for clutching the cylinder shown in FIGURES l3 and 14 with a power source;

FIGURE 16 is an exploded schematic perspective view of the power means utilized in driving the several component elements of this invention;

FIGURE 17 is a schematic flow diagram illustrating the primary steps of the folding apparatus from the point the flexible sheet is started therethrough to and including the discharge thereof to the stacking mechanism;

FIGURE 18 is a fragmentary side elevational view similar to FIGURE 9 but showing a counting mechanism attached to the apparatus;

FIGURE 19 is a front perspective view of the counting device, per se;

FIGURE 20 is a back perspective view of the counting device;

FIGURE 21 is an exploded perspective view of the counting device; and,

FIGURE 22 is a schematic wiring-diagram of the electrical control elements utilized in effecting the first fold of the sheet material, the second fold, and the electrical component of the sheet counting device.

Referring now more specifically to the drawings, reference numeral 10 designates, in general, apparatus for continuously folding and stacking flexible sheet material, the apparatus or device being constructed in accordance withthe teachings of this invention. The apparatus 10 is seen to comprise an open substantially rectangular main frame 12 including a pair of laterally spaced and substantially parallel side frame members 14, 16 having each of their respective adjacent pairs of ends rigidly connected together by means of a pair of longitudinally spaced substantially parallel end frame members 18, 20, see FIGURES 1, 2 and 5. Intermediate the end frame members 18, 20 is disposed and transversely extends a cross-frame member 22, the opposed ends of which are rigidly connected to the side frame members 14, 16. A plurality of standards 24, 26, 28, 30, 32 and 34 support the main frame 12 and are connected at their respective upper ends thereto and to the terminal ends of the end and cross-frame members 18, 20 and 22, respectively. Between each laterally spaced pair of standards 24, 30 and 26, 32, and 28, 3 4, respectively, extend cross-braces 36, 38 and 40. Between the pairs of standards 24, 26 and 26, 28 at one side of the main frame 12 extend reinforcing frame members 42, 44, respectively, and at the other side thereof a reinforcing frame member 46 extends between the pair of standards 30, 32.

Reference numerals 48, 50 denote a pair of elongated substantially rectangular plates which are secured to the upper sides of the end and cross-frame members 18, 20, 22 and to the adjacent sides of the side frame members 14, 16. The adjacent edges of the plates 48, 50 are laterally spaced from each other to form an elongated open ended substantially rectangular slot 52 therebetween to serve a function to be described, and the upper surfaces thereof are given a smooth finish. The plates 48, 50, intermediate their respective ends are provided with elongated substantially rectangular slots as are designated at 53, 54, which also serve a purpose to be described below.

A shaft 56 extends coaxially through a solid cylindrical roller 58 and projects beyond the opposed ends thereof, the projecting ends of the shaft 56 being supported for rotation in a pair of identical confronting journals 60 which depend from the side frame members 14, 16 adjacent an end of the frame 12, this end of the frame being designated, for reference purposes, by the letter F to denote the feeding end of the machine or apparatus 10. At the other end of the main frame 12 and depending from the side frame members 14, 16 are a pair of depending confronting journals 62 which rotatably receive and support the opposed ends of a shaft 64 on which is coaxially mounted a second cylindrical roller 66 of identical size with respect to the roller 58. The aforementioned other end of the main frame 12 comprises the discharge end of the machine 10 and is designated by the reference letter D.

A plurality of endless belts 68 are trained around the rollers 58, 66 and the under sides thereof slidably engage and track against the upper sides of the plates 48, 50 when the shaft 64 is driven. The driving means for the shaft 64 includes an electric motor 69 fixedly secured to a bracket 70 which depends from the side frame member 14 intermediate the standards 26, 28. The drive shaft 72 of the motor 69 has rigidly mounted thereon a drive pulley '74 which is aligned with a speed reducing pulley 76 fixed for rotation with and mounted on a driven shaft 78. The opposed ends of the shaft 78 are journalled for rotation and are supported in a pair of confronting journals 80 'fixedly mounted on the cross-braces 38, 40. An endless pulley belt 82 is trained around the drive'and driven pulleys 74, 76 to effect rotation of the shaft 78, and the outer end of the latter has fixed thereon for rotation therewith a second driven pulley 84. The cylindrical roller 66 has secured thereto for rotation therewith a pulley 86 aligned with the pulley 84, and an endless pulley belt 88 having a substantially 180 degree twist is trained around the pulleys 84, 86 to establish a driving relation therebetween (see FIGURES 5 and 16). Referring now more specifically to FIGURES 2, Sand 11 to 15, inclusive, it is seen that an elongated shaft 90 extends transversely across the central portions of the slots 53,54, and the opposed ends thereof are journalled for rotation in the leg portions 92 of a pair of confronting identical L-shaped brackets 94 which project above their respective foot portions 96, the latter being fixedly secured by conventional means to the side frame members 14, 16.

Journalled for free rotation on the shaft 90 adjacent the opposed end thereof are a pair of substantially hollow cylindrical collars 98, 100 having oppositely directed hubs 102, 104, respectively, which terminate at their respective outer ends in outwardly extending radial flanges 106, 108. The collars, hubs and flanges are all formed of a magnetizable material to serve a function to be described.

clearly seen in FIGURE 12, the shaft 90 is freely rotatable within the apertures 120, 122 formed in the end walls 116, 118, and the latter are coaxially aligned with respect thereto.

Mounted within the housing 112 is a conventional electromagnetic brake coil 124 which is coaxially disposed in spaced relation with respect to the shaft 90, and an annular armature 126, both of which are fixedly secured within the housing 112 against rotation with the shaft 90. At the other end of the shaft 90 and keyed thereto for rotation therewith is a winding 'or coil 1-28 of an electro-magnetic clutch, the coil 128 having an annular armature 130 at one end thereof disposed in confronting relation relative to the flange 108, and as seen in the drawings, the winding 128 is disposed within the housing 114. The other end of the winding 128 carries an annular wiping ring 132 which is engaged by a stationary brush 134 mounted on the end wall 118. clutch is conventional in the art.

To effect rotation of the shaft 90 a pulley 136 is This electro-magnetic mounted for rotation with the shaft 90 on that end thereof adjacent the clutch winding 128 (see FIGURES 2, 4 and 16) and is aligned with another pulley 138 fixedly secured on that end of the shaft 64 adjacent the pulley 62. Adjacent the roller 110 and positioned proximate -the feed side thereof is a vertical support plate 140 having a laterally projecting flange 142 secured to the side frame member 14. Rotatably mounted on the plate 140 is a pair of vertically spaced idler pulleys 144, 146 disposed in alignment with the pulleys 136, 138. An endless ,belt 148 is trained around the pulleys 138, 144, 146 and passes under the pulley 1'36 in driving relation with respect thereto.

Referring again specifically to FIGURES 11 to 15, in-

- elusive, it is seen that the roller has rigidly secured thereto a pair of axially spaced and aligned bosses 150, 152

which rotatably receive and support a shaft 154, the ends of the latter projecting beyond the bosses and terminate in laterally offset arms 156, 158 on which are rotatably mounted a pair of coaxially aligned rollers 160, 162. The rollers are adapted to trace a pair of identically shaped substantially circular cam tracks 164 fixedly secured to the leg portions 92 of the two brackets 94, respectively, by

, means of bolts 166, and to the plates 48, 50 by means of welds 168 (see FIGURE 13). The cam tracks 164 each comprise a pair of a-rcuate sections 170, 172 of which the arcuate section 170 is constructed on a radius greater than the radius of the arcuate section 172, and the latter terminates at its respective ends in reversely turned terminals forming inwardly extending shoulders 174, 17-6.

Fixedly secured to the shaft '154 are one of the ends of a plurality of arcuately shaped article clamping tines 178, 180, 182, 184 and 186. These tines have a length which varies between substantially one-quarter to onethird of the circumference of the roller 1 10. As is seen in FIGURES l1 and 13, the lower ends of the tines normally rest in their inoperative non-clamping position in the slots 52, 53, 54 in spaced relation relative to the roller (see FIGURE 13). The tines 178, 180, 182, 184 and 186 are constantly biased to their open or inoperative position by means of a helicoidal spring 188 which surrounds the shaft 154 intermediate the tines 178, and has one of itsends 190 anchored in the boss 150 and its other end 192 engaged under the tine 180.

Mounted on the roller 110 adjacent the brake end thereof is an annular cam 194 having a high side 196 and a low side '198 (see FIGURE 15) Secured to the leg portion 92 of the bracket 94 (see FIGURE 11) is a microswitch 200 having a vertically reciprocal operating lever 202. The micro-switch 200 is normally closed with the operating lever 202 engaging against the low side 198 of the earn 194.

Supported on the upper ends of the foot portions 92 of the brackets 94 and extending transversely between the side frame members 14, 16 are a pair of spaced and substantially parallel bars 204, 206 which carry clamps 208, 210 which engage over and secure to the bars 204, 206 the casing 212 of a photoelectric cell 214. Immediately below the photoelectric cell 214 and secured to the adjacent edges of the plates 48, 50 is an electric light source 216 from which emitted light rays normally pass through the slot 52 to impinge against the photoelectric cell 214.

Referring now to FIGURES 2 and 3, it is seen that adjacent the discharge end D are mounted a pair of L- shaped angle irons 218which support upright struts 220 across the top of which extends a cross-strut 222. To one side of the cross-strut 222 is secured a solenoid 224 by means of an L-shaped bracket 226, the solenoid 224 having an armature 228 normally depending therefrom and terminating in a saddle 230 in which is pivotally connected at 232 one end of an elongated substantially rectangular bar 234 which extends through and is pivotally connected at 236 to the lower end of a bifurcated support member 238 rigidly aflixed to a plate 240 mounted on the cross-strut 222. Pivot-ally connected at 239 to the support member 238 above the pivotal connection 236 is one end of a second bar 242, and the respective other ends of the bars .234, 242 are pivot-ally connected at 244, 246 to a link 248 to the lower end of which is connected a folding shoe 250 having a depended elongated folding blade 252 aligned with the slot 52. The arrangement of the bars 234, 242 is such as to maintain parallelism therebetween as the armature 228 is reciprocated whereby the blade 252 reciprocates vertically through and above the slot 52.

A rod 254 has one of its ends fixedly secured to the plate 240 and the other end thereof projects laterally therefrom and has secured thereto one end of a helicoidal spring 256, the other ,end of the latter being connected with the bar 242 to apply a force thereto in order to effect an upward movement thereof when the solenoid 224 is tie-energized whereby the blade is raised to its elevated position as shown in FIGURE 2.

A bracket 258 mounted on the cross-strut 222 secures the casing 260 of a photoelectric cell 262 thereto, the latter normally receiving light rays emitted from an electric light source 264 through an opening 266 (see FIG- URE 3), the source depending from a support bracket 268 connected to the underside of the plate 48.

A pair of rollers 270, 272 are supported on shafts 274, 276 which are journalled for rotation on the end frame and cross members 20 and 22, respectively, the rollers 274, 27 6 being tangentially arranged with the line of tangency normally aligned parallel to the longitudinal axis of the blade 252. The opposed ends of the shaft 2X74 are journalled for movement towards and away from the shaft 276 in housings 278 secured to the end and cross-frame members 20, 22, the shaft 274 being constantly biased for v I V 2,991,671

7 movement towards the shaft 276 under the influence of springs 278 (see FIGURE 3).

The rollers 270, 272 are disposed immediately below the slot 52 and subjacent to the roller 272 is the upper end of an inclined slide 280 supported on a brace 282 (see FIGURE 3) rigidly connected to the underside of a pair of confronting parallel channel members 284, 286 fixedly secured to the standards 32, 34 and projecting laterally therebeyond, the outer ends thereof being connected by an end bar 287.

The channel members 284, 286 comprise a portion of the sheet stacking and counting apparatus 300, and reference is now made more specifically to FIGURES 1, 2, 3 and 6. The sheet stacking and counting device 300 includes an open frame defined by a pair of laterally spaced and substantially parallel side frame members 302, 304 having one of their respective ends connected to the standards 34, 32, respectively, and project laterally therefrom. The other ends thereof are connected to the upper ends of a second pair of standards 306, 308 and are connected together by means of a crossbar 309. Vertical standards 310 connect the outer ends of the frame members 284, 286, 302 and 304. A roller 311 is carried on a shaft 312, the opposed ends of which are mounted for rotation in a pair of confronting journals 314 mounted on the cross braces 38, 40. Another cylindrical member 316 is carried on a shaft 318 the opposed ends of which are mounted for rotation on a pair of confronting journals 320 secured to the upper sides of the side frame members 302, 304 adjacent the respective outer ends. A plurality of laterally spaced and substantially parallel endless belts 324 are trained around the rollers 311 and 316.

Reference numeral 318 denotes an open substantially rectangular elevator frame including a pair of longitudinally extending angle side frame members 320, 322 and substantially flat rectangular front and rear end frame members 324, 326. As is seen in FIGURES 3 and 4, the frame 318 is disposed adjacent to but spaced inwardly from the roller 316 and extends transversely between the side frame members 302, 304. A plurality of laterally spaced substantially L-shaped cylindrical elevator tines 328 have the leg portions 330 thereof extending transversely across the frame 318 in vertically spaced relation relative thereto, while the foot portions 332 thereof project downwardly and are reverted at 334 for welded connection to the rear frame member 326. The leg portions 330 adjacent their respective outer ends are fixedly secured to the front frame member 324 by means of up right spacers 336, and the outer terminal ends thereof are bent upwardly to form abutments 338.

The side frame members 320, 322 are rigidly secured intermediate the ends thereof to the lower ends of a pair of vertically extending substantially rectangular plates 340 (see FIGURES 8 and 9) having a pair of outwardly projecting, vertically spaced rollers 342, 344 mounted thereon. The rollers 342, 344 track between the side walls 346, 348 of a pair of channel shaped vertical guides 350 having their respective bight portions 352 thereof rigidly secured to the side frame members 302, 304 by means of angle members 354.

Mounted in the channel member 286 adjacent one of the channel members 350 is a micro-switch 356 having an actuating arm 358, the switch hereinafter being referred to as the reset switch which serves a function to be described below.

Immediately adjacent the inner end of the frame 318 are the high sides 360 of a pair of substantially triangular cam tracks 362 mounted on the frame members 302, 304 and having horizontal extensions 363, the cam tracks and extensions being disposed in confronting relation and are connected to the side frame members 302, 304 by means of laterally extending side flanges 364. The cam tracks 3.62 are engageable by rollers 366 supported for rotation on the lower ends of a pair of vertically extending substant'ially rectangular plates 368 which slidably engage 8 a the .bights 370 of a pair of oppositely disposed channel members 372. The channel members 372 are rigidly connected at their respective lower ends to a transversely extending substantially rectangular traveling bar 374 which slidably engages the under side of a pair of channel shaped elongated gear rack supports 376 (see FIGURE 6) secured to the frame members 44, 309 and a cross brace 378 (see FIGURE 3). The bights 370 are formed with a pair of vertically spaced and elongated slots 380, 382 adjacent the upper and lower ends thereof, and the sides 384, 386 (see FIGURE 7) serve as guides for a pair of vertically spaced rollers 388, 390 having shafts 392, 394, respectively, which are supported on the upper and lower ends of the plates 368 and the bights 396 of a pair of oppositely disposed substantially parallel channel shaped members 398. As is clearly seen in FIGURE 6, the shafts 392, 394 extend transversely through the slots 380, 382.

To the upper ends of the channel members 398 is secured a tie-in brace 400 to which is secured in spaced relation relative thereto, a reinforcing brace 402, the spacing being obtained by means of spacer members 404. Adjacent the ends of the tie-in brace 400 are secured a pair of angularly disposed trusses 406 having diverging ends fixedly secured to a pair of substantially rectangular slides 408 (see FIGURES l and 6), the slides 408 being disposed for movement within the side frame members 284, 286 on rollers 410. Also secured to the channel members 398 is a transversely extending support bar 412 to which is secured a plurality of laterally projecting tines 414 (see FIGURE 3) arranged in longitudinally spaced relation for interdigitation with the tines 3 30.

A pair of longitudinally extending fitted elements 416 are rotatably supported on the side frame members 302, 304 (see FIGURES 1 and 3) in bosses 418. To the outer end of the threaded elements 416 is fixedly secured an operating handle 420. Extending transversely of the threaded members 416 is a substantially rectangular bar 422 which is connected to the threaded members 416 by couplings 424, the latter being, in turn, threaded connected to the threaded members 416. Mounted on the bar 422 at longitudinally spaced intervals are a plurality of vertical guides 426 in the lower ends of which are telescopically mounted a plurality of shafts 428 having outwardly turned ends 430. The shafts 428 are spring biased for movement away from the guides by means of a helicoidal spring 432. A second series of vertical guide members are designated at 434, the latter being fixedly secured to the end frame member 287.

Slidably mounted within the channel members 376 is a rack gear 436 (see FIGURE 4) interrupted intermediate its ends at 438 giving rise to: a gear rack end portion 440. The interrupted portion 438 is slotted at 442 to receive the head of a pin 444 which is secured to the cross brace 374.

Rotatably supported in bearings 448 are a pair of transversely extending shafts 450, 452, the shaft 450 having pinions 454 fixedly secured thereto for engagement with the rack gear 436. Fixedly secured to the shaft 452 are a pair of pinions 456 which are adapted to engage and disengage with the rack gear 440 under conditions to be described below.

As is clearly seen in FIGURES 3 and 4, one end of a resilient spring 458 is fixedly secured to the cross member 374, and the other end thereof is anchored to the end frame member 309.

Refering now more specifically to FIGURES 18 to 21, inclusive, reference numeral 500 designates, in general, a sheet unit counting device, the unit comprising an L-shaped bracket 502 having a leg portion 504 and foot portion 506, which may be secured by conventional means to either of the side frame members 302, 304. To the leg portion 504 is secured a back plate 506 on which is mounted a miero-switch 508 having an operating arm 510. Immediately below the arm 510 is mounted a disc 512 having a non-stop portion 514 which is adapted to receive the operating arm :10 of the switch 508 once during every three hundred sixty degrees rotation of the disc 512. The disc 512 is fixedly secured on a shaft 516, the shaft 516 projecting through the back plate 506 and the leg portion 504 and has secured on one end thereof an indicating dial 518 having a pointer 520 which is adapted to sweep indicia 522 inscribed or otherwise secured to the back plate 506. The other end of the shaft 516 extends through a front plate 524 and has fixedly secured thereto a ratchet 526.

A ratchet operating lever 528 has one of its ends pivotally connected to the front plate 524, the other end thereof having a pawl 530 normally engaging one of the teeth of the ratchet 526. A second lever 532 is also pivoted at one of its ends to the front plate 524 and is provided with a pawl 534 which also normally engages one of the ratchet teeth of the ratchet 526. As is clearly seen in FIGURES 18, 2.0 and 2l, a spring 536 connects and extends between the upper end of the lever 528' and the lower end of the lever 53-2 to constantly bias these ends of the levers for movement towards each other. A pivot pin 538 pivotally connects the lower end of the lever 528 with an L-shaped rock lever 540, the latter having an extension 542 bent laterally to the longitudinal axis of the lever 540.

Refering now to FIGURE 18, it is seen that the extension 542 is engaged by one of the tines 300 once each time same are elevated in a manner to be described below, the tines effecting pivotal movement of the lever 540 to cause the lever 5 28 to move upwardly and advance the ratchet 526 a distance of one tooth. The pawl 534 on the lever 532 pivots outwardly during the rotation of the ratchet 526 and re-engages therewith upon the descent of the lever 528.

As is seen in FIGURES 4 and 8, the standard or plate 340 has pivotally connected to the upper end thereof one end of a bell crank lever 600, the latter extending through a slot 602 formed in the side frame member 320. The other end of the bell crank lever 600 is connected with the shaft 452 through a link 604 and pivot pin 606. To prevent the overthrow of the bell crank lever 600, the pinions 456 are provided with stop arms 608 which engage against the channel members 376.

Driving means for the rollers 270, 272, 31 1 and 316 is clearly illustrated in FIGURE 16. As shown therein a pulley 700 is fixedly secured to one end of the shaft 78 and is aligned with a pulley 702 carried on the shaft 312. An endless belt 704 is trained around the pulleys 700, 7 02. To the opposed ends of the shaft 312 is fixedly secured a pair of pulleys 706, 708 and the pulley 706 is aligned with a pulley 710 fixedly secured to one end of the shaft 450. An endless belt 712 is trained around the pulleys 706, 710, to establish a driving relation between the shafts 312 and 450. This driving connection is established through a clutch 714 for a purpose to be more fully described below. Aligned with the pulley 708 is a pulley 716 fixedly secured on the shaft 450. Below the pulley 716 and fixedly secured to one of the side frame members is a pulley 718. An endless belt 720 is trained around the pulleys 708, 718 and engages the underside of the pulley 216. The pulley 716 is driven through the agency of the shaft 450 and the shaft 312 upon actuation of a clutch 722.

Between the roller 3 11 and the clutch 722, a pulley 72 4 I is fixedly secured to the shaft 312 for rotation therewith.

The pulley 724 is aligned with the pulley 726 fixedly secured on the roller shaft 276. An endless belt 777 is trained around the pulleys 724, 726.

Reference numeral 900 designates a micro-switch having an actuator member 902, the micro-switch 900 being fixedly secured in the side frame member 286 (see FIG- URE 3). Reference numeral 904 designates another switch having an actuating member 906 normally disposed between the tines 330, the latter serving a function isa still further micro switch 908- having an actuator 910 normally engaged by the front flame member 324.

Having described the component elements of this invention, the operation of the device is as follows.

The electric motor 69 is connected with any suitable source of electrical energy and when energized the same drivm the shaft 72 and the attached pulley 74. This rotary power is transmitted to the pulley 76 through the belt 82 to the shaft 78. Power transmission takes place between the shaft 78 and the shaft 312 through the pulleys 700, 702 and the pulley belt 704. Thus, the rollers 66, 110, and the rollers 311, 316 are continuously driven through the aforesaid drive means and including the endless belts 68 and 324. Simultaneously therewith the rollers 270, 272 are also constantly driven by virtue of the pulleys 724, 726 through the belt 777. Thus it is seen that the conveyor belts 68 and 324 are continuously driven.

Assuming now that the cylindrical roller 110 is in the position illustrated in FIGURES l1 and 13, a sheet of flexible material such as, for example, a towel 2000 is placed on the belts 68 and the same is conveyed toward 2018, a switch arm 2020, a pair of switch contacts 2022,

2024 and a switch arm 2026. Just prior to the time that the leading edge of the sheet of flexible material 2000 ,passes below the photoelectric cell 214 to energize the transistor circuit and consequently the solenoid 2010, the

brake for the roller 110 is energized through the circuit which may be traced from the line 2004, wire 2028, switch arm 2026, switch contact 2024, a switch arm 2030 normally engaging against a switch contact 2032 which connects through wire 2034 with wire 2036 connected to one end of the brake coil 124. The other side of the brake winding or coil 124 connects through wire 2038 and wires 2040 and 2042 to the power line 2006.

Now as the solenoid 2010 is energized the same actuates a switch arm 2044 which engages against a switch -contact 2046 to effect energization of the solenoid 2048 through the following wiring system. The solenoid 2048 is energized through line 2004, 2050, switch arm 2044, variable resistance 2052 and line 2054 to one side of the solenoid 2048. The other side of the solenoid 2048 connects through wire 2056 with the wire 2042 which is in turn connected back to the lead 2006.

The solenoid 2048 now being energized, the switch arm 2026 breaks contact with the switch contact 2024 and is moved into engagement with the switch contact 2022. This breaks the circuit to the brake coil or winding 124 to release the cylindrical member 110 for rotation with the shaft in a manner to be described below.

Simultaneously with the breaking of the switch arm 2026 from the contact 2024 the solenoid 2048 moves the switch am 2020 from its contact 2018 and into engagement with the contact 2016.

Upon the closing of the switch arm 2026 against the switch contact 2022 the clutch winding 128 is energized through the following circuitry. Current flows through the clutch winding 128 through the lead 2004, wires 2050, 2004 and 2028, through switch arm 2026, switch contact 2022, wire 2056, switch arm 2058, switch contact 2060, and wire 2062 to one side of the clutch winding 128. The other side of the winding 128 is connected through wire 2064 to the wire 2040 and wire 2042 to the other side of the power supply lead 2006.

With the clutch winding 128 energized, the cylindrical member 110 is coupled to and rotates with the shaft 90. However, the transistor circuit 2002 includes a pair of resistors 2066, 2068 which serve as time delay means to prevent the energization of the solenoid 2048 until the leading edge of the sheet 2000 has been fed upon the tines 178, 180, 182, 184 and 186 (see FIGURE 13).

Upon the closing of the switch arm 2044 and the attendant energization of the solenoid 2048, the brake 124 is released and the clutch 128 is engaged. With the cylindrical member now rotating in the direction of the arrows as is indicated in FIGURES 13 and 14, the rollers 166 pass the shoulders 176 and force the tines referred to above to close inwardly toward the cylindrical member 110 thereby clamping the leading edge and marginal portions of the sheet to the cylinder. This clamping action is maintained against the resistance of the spring 188 as long as the rollers 166 follow the arcuate sections of the cam tracks 164.

It should be noticed at this point that the solenoid 2070 has been maintained constantly energized prior to the rotation of the cylindrical member 110 through the circuit which reads from the lead 2004, 2050, the normally closed switch 200, and the wire 2072 to one side of the solenoid 2070. The other side of the solenoid 2070 is connected to the other side of the power source through the wires 2040, 2042 and lead 2006.

Now, however, upon the rotation of the cylindrical member 110 the operating lever 202 begins to ride on the high side 196 of the cam 194 and breaks the circuit to the solenoid 2070 by forcing the switch 200 to its open position. The indexing of the cam tracks 196, 198 is such as to permit the cylindrical member 110 to rotate substantially to the position shown in FIGURE 14 prior to the operation of the solenoid 2070.

The leading edge of the sheet-of flexible material 2000 is held in its clamped position as is illustrated in FIG- URE 14 until the trailing edge thereof passes the photoelectric cell 214.

When the micro-switch 200 opens, the solenoid 2070 is de-energized and the switch arms 2030, 2058 close against the switch contacts 2076 and 2078, respectively. This de-energizes the clutch winding 128 and holds the drum or cylindrical member 110 stationary since electrical circuit is again established through the brake coil 124.

The cylindrical member 110 is held stationary until the sheet 2000 moves thereunder to such an extent that the trailing edge thereof passes beyond the photoelectric cell 214. This effects an energization of the solenoid 2010 causing the switch arm 2044 to close against the contact 2046 and consequently energize the solenoid 248 to effect operation of the switch arms 2020, 2026 in the opposite direction thereby de-energizing the brake circuit and reestablishing the circuit to the clutch 128.

The effect of the last sequence of-movements is to recouple the cylindrical member 110 with the shaft 190 causing the further rotation thereof, and as the cylindrical memebr 110 continues its rotation the rollers 166 pass under the shoulders 174 thereby releasing the tines 178, 180, 182, 184 which, under the spring tension of the spring 188 move outwardly away from the roller 110 and thereby effects the release of the leading edge of the sheet material 2000.

The timing of the circuit is such that as the leading edge of the sheet material 2000 leaves the cylindrical member 110, the leading edge of the sheet material 2000 will fall substantially on the trailing edge of the sheet material 2000. Thus, the sheet 2000 has been folded substantially in one-half (see FIGURE 17).

The conveyor belts 68 now carry the folded edge of the sheet 2000 towards the photoelectric cell 262 to effect through a transistor circuit 2080 an actuation of the solenoid 2082. This circuit may be traced fromthe line 2004, wire 2084, the photoelectric cell 262, transistor circuit 2080 and wire 2086 to one side of the solenoid 12 2082. The other side of the solenoid 2082 connects through wire 2088 with the other power line 2006.

As the once folded sheet material passes under the photoelectric cell 262, the solenoid 2082 is energized to close the switch 2092 against the contact 2094 to establish a circuit through the resistor 2096 to a solenoid 2098. This circuit may be traced from the lead 2004, switch arm 2092, switch contact 2094, resistance 2096, wire 2100 to one side of the solenoid 2098. The other side of the solenoid 2098 connects through wire 2102 with the other side of the power source lead 2006.

Upon energization of the solenoid 2098, switch arm 2104 closes against switch contact 2106 to effect energization of a solenoid 2108, the circuitry of which may be traced as follows. Current flows from the line 2004, wire 2110, switch arm 2104, switch contact 2106 to one side of the solenoid 2108, and from the other side of the solenoid 2108 through wire 2112 to the other side of the power source, line 2006.

Upon energization of the solenoid 2108, the armature 228 is moved upwardly to force the folding blade 252 to move downwardly against the once folded sheet 2000 to effect a second fold therein, the blade 252 forcing the folded sheet of material downwardly through the slot 52 and into and between the folding rollers 272, 270.

Immediately after the trailing edge of the first folded sheet of material passes beyond the photoelectric cell 262, the circuit to the solenoid 2108 is broken and the blade 252 returns to its original position.

The now twice folded sheet of material passes downwardly between the rollers 270, 272 and is conveyed on a slide 280 to the conveyor belts 324. The folded sheet of material 2000 moves in the direction of the stacking device, and the leading edge thereof engages against the actuating arm 906 of the microswitch 904. The folded article 2000 closes the normally open micro-switch 904 to energize the solenoid 2200 through the line 2004, wire 2202, wire 2204, switch 904, the normally closed microswitch 900, and the wire 2206 to one side of the solenoid 2200. The other side of the solenoid 2200 connects through wire 2208 and wire 2210 with the other side of the power lead 2206. The effect of the energization of the solenoid 2200 causes the switch arms 2212 and 2214 to close against the switch contacts 2216 and 2218, respectively. The power clutch 722 is thus energized through the lead 2004, wire 2202, wire 2204, switch arm 2214 and its contact 2218 to one side of the clutch winding 72 2. The other side of the power clutch winding 722 is connected to the other power source lead 2006 through wire 2220, wire 2210 and wire 2102.

With the power clutch 722 energized the same couples the pulley 708 to the shaft 312. This, in turn, causes the pulley 716 to rotate in the direction of the arrows shown in FIGURE 16 and forces rotation of the shaft 450. Rotation of the shaft 450 causes the pinions 454 mounted thereon to rotate, and in so rotating, the pinions 454 effect longitudinal movement of the rack gears 436. As the rack gear 436 moves longitudinally to the left, as viewed in FIGURE 4, the end section 440 thereof meshes with the pinions 456 and rotates the shaft 452. Rotation of the shaft 452 actuates the bell crank lever 600 and effects elevation of the plate 340. Elevation of the plate 340 causes the frame 318 to rise and at the same time raises the tines 330. The frame and tines continue to rise until they achieve the dotted line position illustrated in FIGURE 3 and at that time the rack gear extension 440 has passed out of mesh with the pinions 456.

Due to the provision of the slot 442 in the rack gear 438, the transverse bar or connector 374 has remained stationary. However, after the frame 318 has reached its maximum upward position, the pins 444 are engaged by the gear rack 438 at the other end of the slot 442 as viewed in FIGURE 4 and the member 374 is now drawn to the left, reference again being made to FIGURE 4 of the drawings.

As the gear racks 436 continue their respective movements, the plate 368 and channel members 384, 398 move to the left, the roller 366 tracing the upper side of the cam 362, and in so moving, the channel-shaped member 398 is withdrawn from the position shown in full lines in FIGURE 3 and is simultaneously lowered whereby the tines 414 are also moved to the left and lowered to the dotted line position of FIGURE 3.

In so moving, the carriage 408 moves away from the switch actuating member 358 of the switch 356 and closes the same. When the carriage 408 is moved to its maximum distance to the left as viewed in FIGURE 3,

the switch 900 is opened when the carriage 406 strikes against the switch actuator 902, to effect deenergization of the solenoid 2200 with the solenoid 2 200 deenergized, the circuit to the power clutch 722 is broken and the shaft 450 is free to rotate.

It will be recalled that the cross bar 374 is connected to the spring 458, and consequently, as soon as the shaft 450 is freed from its actuating power source, the rack gears 436 and the extensions 440 move in the opposite direction under the influence of the spring 458. This movement efiects reengagement of the rack gear extension 4:40 with the pinion 456 and simultaneously moves the standard 336 and the interconnected U-shaped channel members 384, 398 in the opposite direction in such a manner that the tines 414 move forwardly and below the tines 330 to raise the sheet of flexible material therefrom. As the pinion 456 continues to be rotated, the tines 330 are moved to their lowermost position below the belts 324. As the tines 330 move downwardly, the "front frame member 324 engages against switch actuating member 9 10 of the microswitch 908 and closes the same to elfect closure of one switch in a circuit to a reset clutch 71 4.

The reset clutch 714 serves to couple the shaft 450 with the shaft 312 to cause the shaft 450 to rotate in the opposite direction from that described above. This has the eflfect of slowing down the return of the gear racks 436, and as the same approach their full line positions illustrated in several [figures of the drawings, the carriage 408 pinches against the switch actuating member 356 to open the microswitch 356 to effect the energization of the reset clutch.

Energization of the power clutch 722 may be traced through the following circuitry. Current is taken from the lead 2004, Wire 2204, switch am 2214, switch contact 2218 to one side of the winding of the clutch 722. Wire 2220 connects the other side of the winding for the clutch 722 to the wire 2210 and back to the other side of the power source through wire 2102.

The reset clutch 714 is energized by the circuitry which includes the lead 2004, wire 2202, wire 2204, switcharm 2214, switch contact 2224, wire 2226, switch arm 356, wire 2228, switch 908, and the wire 2230 to one side of the coil of the reset clutch 714. The other side of the clutch 714 is connected by wire 2210 to the wire 2102 which is, in turn, connected to the lead 2006.

The sheet counting device and its operation has been described in detail above. However, this device is unique in one respect. It will be recalled that the microswitch 508 is actuated by a switch arm 510 every 360 degrees of the rotation of the disc 512. The switch 508 is normally open and closes upon the stacking of the 25th one of the folded articles.

At the time the switch 508 is closed a resistance capacitance circuit is established in the circuit to the solenoid 2098 establishing a time delay in the energization thereof which, in turn, delays the closing of the switch arm 2004 to effect energization of the solenoid 2008. This permits the first folded article to travel a little beyond the other articles stacked therebefore so that as this 25th folded article is stacked, an edge thereof will project beyond the 24 articles previously stacked. This gives rise to visual means for calculating the number of stacked articles.

'14 Having described and illustrated in detail one embodiment of this invention, it will be.understood that the same is offered merely by Way of example, and that this invention is to be limited only by thescope of the appended claims.

What is claimed is: 1. A flexible sheet folder comprising, a powered, elongated sheet conveying surface continuously movable in a g ven direction, a rotatable pick-up means extending transversely over said conveyor in clearing relation relative thereto, and being adapted to rotate through selected arch in a cyclic sequence and with the under surface thereof, adjacent to the conveying surface, moving in the same direction as the conveying surface, said pick-up means being adapted to grasp the leading edge of a sheet carried on the moving conveying surface and to rotate through an arc sufficient to elevate and substantially overturn the leading edge thereof to commence a sheet folding movement, means responsive to the travel of the leading edge of said sheet to automatically operate and to effect said grasping and partial rotation of said pick-up means as the leading edge of the sheet moves to a grasping position under the pick-up means, said pick-up means .being further adapted to release said leading edge to rotate through an arc sufficient to return it to its initial position as the sheet is folded and means responsive to the travel of the trailing edge thereof to automatically operate and to effect said release and completion of said rotation of said pick-up means as the trailing edge thereof passes under the pick-up means whereby to permit the leading edge to fall upon the sheet adjacent to the trailing edge.

2. A flexible sheet folder, comprising, a power-driven, continuously-moving, elongated, sheet-conveying surface formed by a plurality of laterally spaced, parallel, endless belts engaged about and spanning between a pair of rollers, a rotatable pick-up means extending transversely over and in clearing relation relative to said surface and being adapted to rot-ate through selected arcs in a cyclic sequence with the under surface thereof, adjacent to the conveying surface, moving in the same direction as the conveying surface, and being adapted to clampingly engage the leading edge of a sheet supported upon and moving with the surface and to rotate through an arc suffito the travel of the trail-ing edge of said sheet to actuate said rotatable means to automatically efiect said release and return to the original position.

3. In a machine for folding flexible sheet material,

. having an elongated sheet conveying surface powered for continuous movement in a given direction and being formed by a plurality of laterally spaced, parallel endless belts mounted upon spaced parallel rollers, a pick-up means adapted to grasp, overturn and hold the leading edge of a sheet being carried upon the conveying surface to fold the same and to release the leading edge thereof at the trailing edge to complete the fold, and

including, in combination with the sheet conveying surface, a generally cylindrical roller mounted transversely of and in clearing relation above the conveying surface,

a plurality of tines pivotally mounted upon the roller in a transverse array with respect to the conveying surface with the free ends thereof being adapted to swing away from the roller to an open position and to lie in the spaces between said endless belts facing the direction of conveyor movement, when the roller is at its initial non-operative position, a sensing means adapted to produce a first impulse responsive to the movement of the actuating means operative responsive to said first impulse to move the tines against the roller as the leading edge of the sheet moves between the tines and the roller and to rotate the roller in the direction of the sheet movement through a first arc sufiicient to elevate and substantially overturn the leading edge of the sheet and operative responsive to said second impulse to move the tines away from the roller to release the leading edge of the sheet and continue rotation of the roller through a second arc to completely revolve the roller to its initial position with the tines lying in the spaces between the endless belts.

4. In the organization defined in claim 3, said tines being mounted upon a common shaft pivotally carried upon the roller, and having a follower arm, and said actuating means including a two-lobed cam about the roller, said follower arm engaging the cam, one lobe of the cam being adapted to shift the follower to hold the tines in their open position and the second lobe of the cam being adapted to hold the tines in their closed position, and wherein the cam is set so that the follower engages the first lobe when the roller is in said normal, non-operative position and engages the second lobe as the roller commences rotation responsive to the said first impulse, remains in engagement with the second lobe as the roller rotates through the said first arc and returns to the first lobe as the roller commences rotation responsive to the said second impulse.

5. In the organization defined in claim 3, said actuating means including a continuously rotating axially aligned shaft extending through the roller, a brake means adapted to engage the roller to hold it against rotation, a clutch means adapted to engage the shaft and the roller to rotate the roller by the movement of the shaft, shifting means adapted to alternately engage and disengage said brake means and clutch means, with the brake means being engaged and the clutch means being disengaged when the roller is in its normal non-operative position said shifting means being adapted to be shifted responsive to said first and second impulses to disengage the brake means and engage the clutch means to commence movement of the roller through said arcs, and stop-switch means located in correlation with the terminal points of said arcs, adapted to shift the shifting means to engage the brake means and disengage the clutch means to stop movement of the roller when it rotates through one of said arcs.

6. In the organization defined in claim 5, said brake means and clutch means including solenoids and said stop-switch means including a cam carried by the roller having two steps and a switch having a finger actuator operable to selectively open and close responsive to movement over the steps as the roller rotates and a three-way switching circuit interengaging the switch with the impulse-producing sensing means whereby to produce a sequential shifting of the brake-clutch solenoids.

7. In the organization defined in claim 3, wherein the rate of rotation of said roller is correlated with the speed of movement of said surface whereby to permit a pick-up and overturning of the leading edge of the sheet without jerking or piling up of the same.

8. In a machine for folding flexible sheet material, hav- 16 ing an elongated sheet conveying surface powered for continuous movement in a given direction, a pick-up means adapted to grasp, overturn and hold the leading 'edge of a sheet being carried upon the conveying surface and to release the leading edge thereof at the trailing edge to complete the fold and including, in combination, with the sheet conveying surface, a generally cylindrical roller mounted transversely of and in clearing relation above the conveying surface, gripping means mounted on the roller being adapted to extend from the roller to lie at the conveyor surface facing the direction of conveyor movement and being adapted to receive the leading edge of a sheet being carried upon the conveying surface, a sensing means adapted to produce a first impulse responsi-ve to the movement of the leading edge of a sheet being carried upon the conveying surface and approaching the roller, and to produce a second impulse responsive to the movement of the trailing edge of the sheet approaching the roller, and actuating means responsive to said first impulse adapted to grip the leading edge of the sheet as it contacts the gripping means and to rotate the roller in the direction of sheet movement through a first arc sufiicient to elevate and substantially overturn the leading edge of the sheet and being operative responsive to said second impulse to open the gripping means to release the leading edge of the sheet and continue the rotation of the roller through a second arc to return it to its initial position with the gripping means being open and adapted to receive the leading edge of another sheet being carried upon the conveying surface.

9. A flexible sheet folder comprising, a powered, elongated sheet conveying surface continuously movable in a given direction, a rotatable pick-up means extending transversely over said conveyor in clearing relation relative thereto, and being adapted to rotate through selected arcs in a cyclic sequence and with the under surface thereof, adjacent to the conveying surface, moving in the same direction as the conveying surface, said pick-up means being adapted to grasp the leading edge of a sheet carried on the moving conveying surface and to rotate through an are sufficient to elevate and substantially overturn the leading edge thereof to commence a sheet folding movement, means adapted to automatically operate and effect said grasping and partial rotation of said pickup means as the leading edge of the sheet moves to a grasping position .under the pick-up means, said pick-up means being further adapted to release said leading edge to rotate through an arc suflicient to return it to its initial position as the sheet is folded and means adapted to automatically operate and to effect said release and completion of said rotation of said pick-up means as the trailing edge thereof passes under the pick-up means whereby to permit the leading edge to fall upon the sheet adjacent to the trailing edge.

References Cited in the file of this patent UNITED STATES PATENTS 1,670,974 Mayer May 22, 1928 2,224,606 Neckel Dec. 10, 1940 2,282,127 Gabbert May 5, 1942 2,545,798 Sjostrom Mar. 20, 1950 2,621,927 Swift Dec. 16, 1952 2,645,476 Wood et a1. July 14, 1953 2,650,821 Howlett Sept. 1, 1953 2,740,627 Woodward Apr. 3, 1956 2,106,953 Ludewig Feb. 1, 1958 

